Author: Charles Burnett YeamansPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Dry process fluorination of uranium dioxide using ammonium bifluoride : thesis
Author: Charles Burnett YeamansPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Dry Process Fluorination of Uranium Dioxide Using Ammonium Bifluoride
Author: Charles Burnett YeamansPublisher:
ISBN:
Category :
Languages : en
Pages : 86
Book Description
An experimental study was conducted to determine the practicality of various unit operations for fluorination of uranium dioxide. The objective was to prepare ammonium uranium fluoride double salts from uranium dioxide and ammonium bifluoride, then decompose these salts to uranium tetrafluoride through heating to temperatures near 425 °C in either a fluidized bed or a stirred bed. Fluorination in the stirred bed was attempted without pretreatment of the reagents. For the fluidized bed experiments, reagents were ball-milled prior to being heated in the bed. Experiments were conducted in either argon or 4% hydrogen in argon. The ball mill appeared to be an effective technique for fluorinating uranium dioxide with ammonium bifluoride. Samples changed color from brown to bright green, and no oxides could be detected in the x-ray diffraction pattern of the product. It was found that stainless steel is a suitable material of construction for reaction vessels, whereas mild steel parts corroded quickly. Only a small degree of fluidization provided adequate mixing in fluidized beds, but a paddle mixing the stirred beds left an unmixed region around the bed perimeter. Results from the stirred beds showed the initial fluorination reaction completed only when the reagents were heated to 110 °C for at least three hours under argon. Decomposition took place under argon with a temperature ramp up to 425 °C. The product UF4 contained less than 1% oxide as an impurity, and the decomposition appeared to be complete. Fluidized beds were run with both argon and 4% hydrogen in argon as carrier gases. Experiments with 4% hydrogen in argon produced uranium tetrafluoride, with ammonium uranium pentafluoride and uranium dioxide as impurties. Experiments in argon produced uranium tetrafluoride, with uranyl difluoride, ammonium diuranyl pentafluoride and triuranium octoxide as impurities. Minimum temperatures and times needed to decompose the double salt in the fluidized beds were 200 minutes at 115 °C, a 500-minute ramp to 425 °C, and 200 minutes at 425 °C. The intermediate double salt produced at 110 °C appeared to be triammonium uranium septafluoride.
The Fluorination of Uranium from Dried Solids and Its Application to the Fluoride Volatility Process
Author: Carl E. JohnsonPublisher:
ISBN:
Category : Fluorination
Languages : en
Pages : 42
Book Description
The ADF fluoride volatility process employs the unit processes of dissolution, fluidized bed drying and fluorination to recover fissile material from reactor fuels. Variables that affect the removal from dried solids representative of those obtained from dissolver solutions of high zirconium alloy fuels were studied. Variables investigated were particle size, additives, temperature, time, hydrofluorination and pyrolysis. Application of the study of Dresden and APPR type fuels was also considered.
Synthesis of Uranium Fluorides from Uranium Dioxide with Ammonium Bifluoride and Ammonolysis of Uranium Fluorides to Uranium Nitrides
Author: Charles Burnett YeamansPublisher:
ISBN:
Category :
Languages : en
Pages : 270
Book Description
Laboratory Investigations in Support of Fluid Bed Fluoride Volatility Processes
Author: R. L. JarryPublisher:
ISBN:
Category : Fluidized reactors
Languages : en
Pages : 46
Book Description
Work in the development of fluid-bed fluoride volatility processes is described. In these processes, uranium and plutonium in spent nuclear fuels are converted into hexafluoride compounds in a fluid-bed reactor. The uranium and plutonium hexafluorides are volatile and can be separated from fission products, cladding, and alloying materials by techniques such as vaporization and distillation. The experimental work was directed toward devising a fluorination procedure for uranium and plutonium dioxides which would result in a high degree of removal of uranium and plutonium as hexafluorides.
Large Scale Tests of the Aqueous Hydrogen Fluoride Process for the Production of Uranium Tetrafluoride
Author: G. J. VogelPublisher:
ISBN:
Category : Hydrogen fluoride
Languages : en
Pages : 16
Book Description
The Use of Ammonium Bifluoride in the Preparation of Fluorides from Oxides
Author: John Reed LongPublisher:
ISBN:
Category : Ammonium compounds
Languages : en
Pages : 80
Book Description
A Continuous Process for Converting Uranium Dioxide to Uranium Tetrafluoride Using Aqueous Hydrogen Fluoride
Author: S. D. SchiffmanPublisher:
ISBN:
Category : Hydrogen fluoride
Languages : en
Pages : 14
Book Description
The Fluorination of Uranium from Dried Solids and Its Application to the Fluoride Volatility Process
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The fluorination of uranium from dried solids representative of those obtained from the fluid-bed drying of dissolver solutions of high zirconium alloy fuels. e.g. Dresden and Army Package Power Reactor fuels, was studied under a variety of conditions. Variables investigated were particle size, additives, temperature, time. hydrofluorination, and pyrolysis. Temperatures in excess of 650 deg C were needed to ensure complete removal of uranium from the solid. Pyrolysis with HF of previously fluorinated materials aided in uranium removal from the zirconium solid. (C.J.O.).
Engineering Development of Fluid-bed Fluoride Volatility Processes
Author: G. J. VogelPublisher:
ISBN:
Category : Fluorination
Languages : en
Pages : 112
Book Description
Fluid-bed, fluoride volatility processes are being developed for the recovery of uranium and plutonium from spent nuclear fuels for power reactors. In these processes, chemical separations are achieved by formation of the volatile hexafluoride compounds of uranium and plutonium.